__attribute__((alias)) variable attribute

Aliases must be declared in the same translation unit as the definition of the original variable.

In the output object file, the compiler replaces alias references with a reference to the original variable name, and emits the alias alongside the original name. For example:

int oldname = 1;
extern int newname __attribute__((alias("oldname")));

This code compiles to:

        .type   oldname,%object         @ @oldname
        .data
        .globl  oldname
        .align  2
oldname:
        .long   1                       @ 0x1
        .size   oldname, 4
        ...
        .globl  newname
newname = oldname

Example

#include <stdio.h>
int oldname = 1;
extern int newname __attribute__((alias("oldname"))); // declaration
void foo(void){
    printf("newname = %d\n", newname); // prints 1
}